Evaluation of interactive forces between alkaline earth metal fluoride particles and single crystal substrate using atomic force microscopy

Interactive forces between particles play an important role in diverse fields of science and technology. With the advent of Atomic Force Microscopy, investigation of interactive forces has been extended to micro and nano-scale particles with new applications. These forces are known to vary with the dimension of the particles and with the different levels of humidity. In the present paper we have investigated the interactive forces between a spherical particle probes of eutectic BaF2-CaF2 and a single crystal surface of CaF2 using an Atomic Force Microscope. The effect of humidity on the interactive forces has been examined by analyzing the force-displacement curves at controlled levels of humidity. Force distance curves obtained with two different probes, 5 μm and 17 μm in diameter, and have been examined to investigate the effect of probe dimensions. The results are discussed in view of the application of eutectic BaF2-CaF2 particles in self-lubricating coatings for aerospace applications.

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